// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: https://codemirror.net/LICENSE

"use strict";

import * as CodeMirror from "codemirror";

var HINT_ELEMENT_CLASS = "CodeMirror-hint";
var ACTIVE_HINT_ELEMENT_CLASS = "CodeMirror-hint-active";

// This is the old interface, kept around for now to stay
// backwards-compatible.
CodeMirror.showHint = function (cm, getHints, options) {
    if (!getHints) return cm.showHint(options);
    if (options && options.async) getHints.async = true;
    var newOpts = {hint: getHints};
    if (options) for (var prop in options) newOpts[prop] = options[prop];
    return cm.showHint(newOpts);
};

CodeMirror.defineExtension("showHint", function (options) {
    options = parseOptions(this, this.getCursor("start"), options);
    var selections = this.listSelections()
    if (selections.length > 1) return;
    // By default, don't allow completion when something is selected.
    // A hint function can have a `supportsSelection` property to
    // indicate that it can handle selections.
    if (this.somethingSelected()) {
        if (!options.hint.supportsSelection) return;
        // Don't try with cross-line selections
        for (var i = 0; i < selections.length; i++)
            if (selections[i].head.line != selections[i].anchor.line) return;
    }

    if (this.state.completionActive) this.state.completionActive.close();
    var completion = this.state.completionActive = new Completion(this, options);
    if (!completion.options.hint) return;

    CodeMirror.signal(this, "startCompletion", this);
    completion.update(true);
});

CodeMirror.defineExtension("closeHint", function () {
    if (this.state.completionActive) this.state.completionActive.close()
})

function Completion(cm, options) {
    this.cm = cm;
    this.options = options;
    this.widget = null;
    this.debounce = 0;
    this.tick = 0;
    this.startPos = this.cm.getCursor("start");
    this.startLen = this.cm.getLine(this.startPos.line).length - this.cm.getSelection().length;

    var self = this;
    cm.on("cursorActivity", this.activityFunc = function () {
        self.cursorActivity();
    });
}

var requestAnimationFrame = window.requestAnimationFrame || function (fn) {
    return setTimeout(fn, 1000 / 60);
};
var cancelAnimationFrame = window.cancelAnimationFrame || clearTimeout;

Completion.prototype = {
    close: function () {
        if (!this.active()) return;
        this.cm.state.completionActive = null;
        this.tick = null;
        this.cm.off("cursorActivity", this.activityFunc);

        if (this.widget && this.data) CodeMirror.signal(this.data, "close");
        if (this.widget) this.widget.close();
        CodeMirror.signal(this.cm, "endCompletion", this.cm);
    },

    active: function () {
        return this.cm.state.completionActive == this;
    },

    pick: function (data, i) {
        var completion = data.list[i], self = this;
        this.cm.operation(function () {
            if(completion){
                if (completion.hint)
                    completion.hint(self.cm, data, completion);
                else
                    self.cm.replaceRange(getText(completion), completion.from || data.from,
                        completion.to || data.to, "complete");
                CodeMirror.signal(data, "pick", completion);
            }
            self.cm.scrollIntoView();
        })
        this.close();
    },

    cursorActivity: function () {
        if (this.debounce) {
            cancelAnimationFrame(this.debounce);
            this.debounce = 0;
        }

        var identStart = this.startPos;
        if (this.data) {
            identStart = this.data.from;
        }

        var pos = this.cm.getCursor(), line = this.cm.getLine(pos.line);
        if (pos.line != this.startPos.line || line.length - pos.ch != this.startLen - this.startPos.ch ||
            pos.ch < identStart.ch || this.cm.somethingSelected() ||
            (!pos.ch || this.options.closeCharacters.test(line.charAt(pos.ch - 1)))) {
            this.close();
        } else {
            var self = this;
            this.debounce = requestAnimationFrame(function () {
                self.update();
            });
            if (this.widget) this.widget.disable();
        }
    },

    update: function (first) {
        if (this.tick == null) return
        var self = this, myTick = ++this.tick
        fetchHints(this.options.hint, this.cm, this.options, function (data) {
            if (self.tick == myTick) self.finishUpdate(data, first)
        })
    },

    finishUpdate: function (data, first) {
        if (this.data) CodeMirror.signal(this.data, "update");

        var picked = (this.widget && this.widget.picked) || (first && this.options.completeSingle);
        if (this.widget) this.widget.close();

        this.data = data;

        if (data && data.list.length) {
            // if (picked && data.list.length == 1) {
            //     this.pick(data, 0);
            // } else {
                this.widget = new Widget(this, data);
                CodeMirror.signal(data, "shown");
            // }
        }
    }
};

function parseOptions(cm, pos, options) {
    var editor = cm.options.hintOptions;
    var out = {};
    for (var prop in defaultOptions) out[prop] = defaultOptions[prop];
    if (editor) for (var prop in editor)
        if (editor[prop] !== undefined) out[prop] = editor[prop];
    if (options) for (var prop in options)
        if (options[prop] !== undefined) out[prop] = options[prop];
    if (out.hint.resolve) out.hint = out.hint.resolve(cm, pos)
    return out;
}

function getText(completion) {
    if (typeof completion == "string") return completion;
    else return completion.text;
}

function buildKeyMap(completion, handle) {
    var baseMap = {
        Up: function () {
            handle.moveFocus(-1);
        },
        Down: function () {
            handle.moveFocus(1);
        },
        PageUp: function () {
            handle.moveFocus(-handle.menuSize() + 1, true);
        },
        PageDown: function () {
            handle.moveFocus(handle.menuSize() - 1, true);
        },
        Home: function () {
            handle.setFocus(0);
        },
        End: function () {
            handle.setFocus(handle.length - 1);
        },
        Enter: handle.pick,
        Tab: handle.pick,
        Esc: handle.close
    };

    var mac = /Mac/.test(navigator.platform);

    if (mac) {
        baseMap["Ctrl-P"] = function () {
            handle.moveFocus(-1);
        };
        baseMap["Ctrl-N"] = function () {
            handle.moveFocus(1);
        };
    }

    var custom = completion.options.customKeys;
    var ourMap = custom ? {} : baseMap;

    function addBinding(key, val) {
        var bound;
        if (typeof val != "string")
            bound = function (cm) {
                return val(cm, handle);
            };
        // This mechanism is deprecated
        else if (baseMap.hasOwnProperty(val))
            bound = baseMap[val];
        else
            bound = val;
        ourMap[key] = bound;
    }

    if (custom)
        for (var key in custom) if (custom.hasOwnProperty(key))
            addBinding(key, custom[key]);
    var extra = completion.options.extraKeys;
    if (extra)
        for (var key in extra) if (extra.hasOwnProperty(key))
            addBinding(key, extra[key]);
    return ourMap;
}

function getHintElement(hintsElement, el) {
    while (el && el != hintsElement) {
        if (el.nodeName.toUpperCase() === "LI" && el.parentNode == hintsElement) return el;
        el = el.parentNode;
    }
}

function Widget(completion, data) {
    this.completion = completion;
    this.data = data;
    this.picked = false;
    var widget = this, cm = completion.cm;
    var ownerDocument = cm.getInputField().ownerDocument;
    var parentWindow = ownerDocument.defaultView || ownerDocument.parentWindow;

    var hints = this.hints = ownerDocument.createElement("ul");
    var theme = completion.cm.options.theme;
    hints.className = "CodeMirror-hints " + theme;
    this.selectedHint = data.selectedHint || 0;

    var completions = data.list;
    for (var i = 0; i < completions.length; ++i) {
        var elt = hints.appendChild(ownerDocument.createElement("li")), cur = completions[i];
        var className = HINT_ELEMENT_CLASS + (i != this.selectedHint ? "" : " " + ACTIVE_HINT_ELEMENT_CLASS);
        if (cur.className != null) className = cur.className + " " + className;
        elt.className = className;
        if (cur.render) cur.render(elt, data, cur);
        else elt.appendChild(ownerDocument.createTextNode(cur.displayText || getText(cur)));
        elt.hintId = i;
    }

    var container = completion.options.container || ownerDocument.body;
    var pos = cm.cursorCoords(completion.options.alignWithWord ? data.from : null);
    var left = pos.left, top = pos.bottom, below = true;
    var offsetLeft = 0, offsetTop = 0;
    if (container !== ownerDocument.body) {
        // We offset the cursor position because left and top are relative to the offsetParent's top left corner.
        var isContainerPositioned = ['absolute', 'relative', 'fixed'].indexOf(parentWindow.getComputedStyle(container).position) !== -1;
        var offsetParent = isContainerPositioned ? container : container.offsetParent;
        var offsetParentPosition = offsetParent.getBoundingClientRect();
        var bodyPosition = ownerDocument.body.getBoundingClientRect();
        offsetLeft = (offsetParentPosition.left - bodyPosition.left - offsetParent.scrollLeft);
        offsetTop = (offsetParentPosition.top - bodyPosition.top - offsetParent.scrollTop);
    }
    hints.style.left = (left - offsetLeft) + "px";
    hints.style.top = (top - offsetTop) + "px";

    // If we're at the edge of the screen, then we want the menu to appear on the left of the cursor.
    var winW = parentWindow.innerWidth || Math.max(ownerDocument.body.offsetWidth, ownerDocument.documentElement.offsetWidth);
    var winH = parentWindow.innerHeight || Math.max(ownerDocument.body.offsetHeight, ownerDocument.documentElement.offsetHeight);
    container.appendChild(hints);
    var box = hints.getBoundingClientRect(), overlapY = box.bottom - winH;
    var scrolls = hints.scrollHeight > hints.clientHeight + 1
    var startScroll = cm.getScrollInfo();

    if (overlapY > 0) {
        var height = box.bottom - box.top, curTop = pos.top - (pos.bottom - box.top);
        if (curTop - height > 0) { // Fits above cursor
            hints.style.top = (top = pos.top - height - offsetTop) + "px";
            below = false;
        } else if (height > winH) {
            hints.style.height = (winH - 5) + "px";
            hints.style.top = (top = pos.bottom - box.top - offsetTop) + "px";
            var cursor = cm.getCursor();
            if (data.from.ch != cursor.ch) {
                pos = cm.cursorCoords(cursor);
                hints.style.left = (left = pos.left - offsetLeft) + "px";
                box = hints.getBoundingClientRect();
            }
        }
    }
    var overlapX = box.right - winW;
    if (overlapX > 0) {
        if (box.right - box.left > winW) {
            hints.style.width = (winW - 5) + "px";
            overlapX -= (box.right - box.left) - winW;
        }
        hints.style.left = (left = pos.left - overlapX - offsetLeft) + "px";
    }
    if (scrolls) for (var node = hints.firstChild; node; node = node.nextSibling)
        node.style.paddingRight = cm.display.nativeBarWidth + "px"

    cm.addKeyMap(this.keyMap = buildKeyMap(completion, {
        moveFocus: function (n, avoidWrap) {
            widget.changeActive(widget.selectedHint + n, avoidWrap);
        },
        setFocus: function (n) {
            widget.changeActive(n);
        },
        menuSize: function () {
            return widget.screenAmount();
        },
        length: completions.length,
        close: function () {
            completion.close();
        },
        pick: function () {
            widget.pick();
        },
        data: data
    }));

    if (completion.options.closeOnUnfocus) {
        var closingOnBlur;
        cm.on("blur", this.onBlur = function () {
            closingOnBlur = setTimeout(function () {
                completion.close();
            }, 100);
        });
        cm.on("focus", this.onFocus = function () {
            clearTimeout(closingOnBlur);
        });
    }

    cm.on("scroll", this.onScroll = function () {
        var curScroll = cm.getScrollInfo(), editor = cm.getWrapperElement().getBoundingClientRect();
        var newTop = top + startScroll.top - curScroll.top;
        var point = newTop - (parentWindow.pageYOffset || (ownerDocument.documentElement || ownerDocument.body).scrollTop);
        if (!below) point += hints.offsetHeight;
        if (point <= editor.top || point >= editor.bottom) return completion.close();
        hints.style.top = newTop + "px";
        hints.style.left = (left + startScroll.left - curScroll.left) + "px";
    });

    CodeMirror.on(hints, "dblclick", function (e) {
        var t = getHintElement(hints, e.target || e.srcElement);
        if (t && t.hintId != null) {
            widget.changeActive(t.hintId);
            widget.pick();
        }
    });

    CodeMirror.on(hints, "click", function (e) {
        var t = getHintElement(hints, e.target || e.srcElement);
        if (t && t.hintId != null) {
            widget.changeActive(t.hintId);
            if (completion.options.completeOnSingleClick) widget.pick();
        }
    });

    CodeMirror.on(hints, "mousedown", function () {
        setTimeout(function () {
            cm.focus();
        }, 20);
    });
    this.scrollToActive()

    CodeMirror.signal(data, "select", completions[this.selectedHint], hints.childNodes[this.selectedHint]);
    return true;
}

Widget.prototype = {
    close: function () {
        if (this.completion.widget != this) return;
        this.completion.widget = null;
        this.hints.parentNode.removeChild(this.hints);
        this.completion.cm.removeKeyMap(this.keyMap);

        var cm = this.completion.cm;
        if (this.completion.options.closeOnUnfocus) {
            cm.off("blur", this.onBlur);
            cm.off("focus", this.onFocus);
        }
        cm.off("scroll", this.onScroll);
    },

    disable: function () {
        this.completion.cm.removeKeyMap(this.keyMap);
        var widget = this;
        this.keyMap = {
            Enter: function () {
                widget.picked = true;
            }
        };
        this.completion.cm.addKeyMap(this.keyMap);
    },

    pick: function () {
        this.completion.pick(this.data, this.selectedHint);
    },

    changeActive: function (i, avoidWrap) {
        if (i >= this.data.list.length)
            i = avoidWrap ? this.data.list.length - 1 : 0;
        else if (i < 0)
            i = avoidWrap ? 0 : this.data.list.length - 1;
        if (this.selectedHint == i) return;
        var node = this.hints.childNodes[this.selectedHint];
        if (node) node.className = node.className.replace(" " + ACTIVE_HINT_ELEMENT_CLASS, "");
        node = this.hints.childNodes[this.selectedHint = i];
        node.className += " " + ACTIVE_HINT_ELEMENT_CLASS;
        this.scrollToActive()
        CodeMirror.signal(this.data, "select", this.data.list[this.selectedHint], node);
    },

    scrollToActive: function () {
        if(this.selectedHint < 0){
            return
        }
        var margin = this.completion.options.scrollMargin || 0;
        var node1 = this.hints.childNodes[Math.max(0, this.selectedHint - margin)];
        var node2 = this.hints.childNodes[Math.min(this.data.list.length - 1, this.selectedHint + margin)];
        var firstNode = this.hints.firstChild;
        if (node1.offsetTop < this.hints.scrollTop)
            this.hints.scrollTop = node1.offsetTop - firstNode.offsetTop;
        else if (node2.offsetTop + node2.offsetHeight > this.hints.scrollTop + this.hints.clientHeight)
            this.hints.scrollTop = node2.offsetTop + node2.offsetHeight - this.hints.clientHeight + firstNode.offsetTop;
    },

    screenAmount: function () {
        return Math.floor(this.hints.clientHeight / this.hints.firstChild.offsetHeight) || 1;
    }
};

function applicableHelpers(cm, helpers) {
    if (!cm.somethingSelected()) return helpers
    var result = []
    for (var i = 0; i < helpers.length; i++)
        if (helpers[i].supportsSelection) result.push(helpers[i])
    return result
}

function fetchHints(hint, cm, options, callback) {
    if (hint.async) {
        hint(cm, callback, options)
    } else {
        var result = hint(cm, options)
        if (result && result.then) result.then(callback)
        else callback(result)
    }
}

function resolveAutoHints(cm, pos) {
    var helpers = cm.getHelpers(pos, "hint"), words
    if (helpers.length) {
        var resolved = function (cm, callback, options) {
            var app = applicableHelpers(cm, helpers);

            function run(i) {
                if (i == app.length) return callback(null)
                fetchHints(app[i], cm, options, function (result) {
                    if (result && result.list.length > 0) callback(result)
                    else run(i + 1)
                })
            }

            run(0)
        }
        resolved.async = true
        resolved.supportsSelection = true
        return resolved
    } else if (words = cm.getHelper(cm.getCursor(), "hintWords")) {
        return function (cm) {
            return CodeMirror.hint.fromList(cm, {words: words})
        }
    } else if (CodeMirror.hint.anyword) {
        return function (cm, options) {
            return CodeMirror.hint.anyword(cm, options)
        }
    } else {
        return function () {
        }
    }
}

CodeMirror.registerHelper("hint", "auto", {
    resolve: resolveAutoHints
});

CodeMirror.registerHelper("hint", "fromList", function (cm, options) {
    var cur = cm.getCursor(), token = cm.getTokenAt(cur);
    var term, from = CodeMirror.Pos(cur.line, token.start), to = cur
    if (token.start < cur.ch && /\w/.test(token.string.charAt(cur.ch - token.start - 1))) {
        term = token.string.substr(0, cur.ch - token.start)
    } else {
        term = ""
        from = cur
    }
    var found = [];
    for (var i = 0; i < options.words.length; i++) {
        var word = options.words[i];
        if (word.slice(0, term.length) == term)
            found.push(word);
    }

    if (found.length) return {list: found, from: from, to: to};
});

CodeMirror.commands.autocomplete = CodeMirror.showHint;

var defaultOptions = {
    hint: CodeMirror.hint.auto,
    completeSingle: true,
    alignWithWord: true,
    closeCharacters: /[\s()\[\]{};:>,]/,
    closeOnUnfocus: true,
    completeOnSingleClick: true,
    container: null,
    customKeys: null,
    extraKeys: null
};

CodeMirror.defineOption("hintOptions", null);
